Oil separator for refrigeration systems



v 7. FeB. l3, 1940. G. W. SMI TH ET-AL OIL SEPARATOR FOR- REFRIGERATIONSYSTEMS Filed Mar a; 9Q 1959 George WJIm/fi A ATTORNEY Patented Feb. 13,1940 on. SEPARATOR FOB REFRIGERATION srs'mms George W. Smith and JamesA. Smith, Lyons,

N. Y., assignors to Kenmore Machine Products, Inc., Lyons, N. '1.

Application March 9, 1939, Serial No. 260,711

5 Claims.

This invention relates to an oil separating device which is adapted foruse in refrigeration systems.

In large refrigeration systems it has been pro-- posed to cause theseparation of oil from the compressed gas while the refrigerant is stillin the vapor phase, that is before it is subjected to condensation, theobjective being to eliminate all oil from the evaporative portions ofthe system and thus to obtain an increased efiectiveness. The practicalsolution of this problem has proved troublesome, not only from amechanical viewpoint, but also for thermal reasons, since sec-' ondarycondensation of refrigerant in the separator induces the. risk of thereturn of liquid refrigerant to the compressor.

In the present invention there is provided a simple and effectiveseparating device which con-- tains a novel regenerative heatingarrangement, by which means the accumulation of liquid refrigerant isentirely prevented. The operation of this separator is wholly automaticin its oil return and heating functions, and it performs thesedutieswithout imposing any discernible additional load on the system.

The more specific aspects of the invention will be more apparent from astudy of the accompanying specification and drawing, wherein:

Fig. 1 is a vertical section through the sepaconnecting the compressorl8 and the condenser II. The separator includes a cylindrical housing Il3 capped by upper and lower heads [4 and I 5 respectively, the formerhead carrying inlet and outlet fittings l6 and I1 connected to theoutlet of the compressor and to the condenser respectively by pipes l8and I9. An oil return fitting 28 is carried low in thewall of thehousing l3, and a pipe 2| which is connected thereto carries separatedoil volumes back to a crankcase fitting 23 on the compressor l0. Studs24 are secured to the lower head I 5 and they serve to mount the unit ona suitable'base B, as indicated in dotted lines in Fig. 1.

A slotted sleeve 25 is secured to the inner end Ito of the fitting l6,and the sleeve carries a filter through lever and needle to provide apivotal asneedle, and the corresponding eflluence of oil 45 mass 26which is retained therein by a cotter pin 21. A perforate washer 21a maybe interposed between the pin and filter mass 26. The outlet fitting I1is formed with a comparatively longer end or barrel lla', which endcontains a bore 32 5 adapted to receive slidably one terminal 28a of aheating coil 28. The coil is formed with a circular section 29 whichrests on the lower head\ l5, and the remainingterminal 28b of the coilextends verticallyalong the wall of the housing l3 10 to a high pointadjacent the upper head i 4.

The oil return fitting 28 is a two-part structure (Fig. 2) consisting ofa valve body 30 and a shouldered pipe bushing 3|, which bushing entersthrough a hole 33 in the housing and is pressed 15 into a bore 34 in thebody 38. The body 30 contains a vertical passage 36 havin atightlyflttedseat insert 31 at its upper e; A n n l of the passageserving as valveneedle 38. A transverse the body establishes commu" a valve seat and thepipe bushing 3|, while a second hole 4| connects the valve passage 36 tothe interior of the housing.

The valve needle 38 is operated by a fioat-- controlled mechanismincluding a float lever 43, one end of which is received within thebifurcated lower extremity 44 of the valve body. A pivot pin 45 extendstransversely through suitable holes in the bifurcations and lever, andit is retained 30 against displacement by a spring clip 46, whose beadedsides 41 anchor over theprojecting ends of the pin (Fig; 3). A verticalhole 48 in the lever receives loosely the projecting lower end of thevalve needle 38. A pin 43 extends transversely 35 sembly. A hollow float58 is-provided with a depending-stud 5| which enters a verticalclearance hole 52 in the free end of the lever. A transverse pin 53provides'an assembly similar to that of 40 the valve needle connection.

It will now be apparent that oil accumulating in the lower end of theseparator will cause the float-controlled opening movement of the valvethrough the seat 31 and thence through the pipe 2| back to the crankcaseof the compressor. In its raised or open position, the-extreme left handportion of the lever 43 engages a stop pin 55to limit further movement.

It is preferred that the housing l3 and upper head l4, together with thefittings thereon, be united by hydrogen welding toiorm a substantiallyintegral structure, into which the float mechanism, heating coil, andfilter pack are late;/

.plied with a ring 51 of a fusible alloy, as shown in Fig. 4, which ringis inserted in the bore 34 of the body 30. When suitable heat isapplied, the

ring 51 melts, and, by capillary flow action. seals not only the pipebushing 3| to the body 30, but

flows about the edges of the housing holev 33 and .thus firmly securesboth parts of the fitting to the housing.'

In the operation of the separator, the relatively hot compressed gasdelivered by the compressor through the pipe l8 impingesdirectly duringtheesubeequent cycle, receives the entire upon the filter mass 26 beforeescaping into the upper portions of the housing l3. Suchimpingexnentencourages the coalescence of oil particles which have .beenentrained with the refrigerant gasesin the compressor l0, andaccordingly the oil drips through the perforate washer 21a. and gathersin a liquid body in the bottom of the housing. The separated gas, in themeantime,

, enters the terminal 281; of the heating coil and finally is directedto the condenser through the, outlet 'fitting l1 and pipe l9.

It will-be appreciated, since the compressor I0 is only intermittentlyoperated in response to load demands of the system, that the compressedrefrigerant gas within the separator will be subject to condensationduring the periods in which the compressor is inactive. As a result,small quantities of liquid refrigerant gather in the oil body 0, andsuch bodies if returned with the 011 during subsequent cycles, create aserious hazard o was of the compressor, as is well I in g -jjagt, Thispossibility is avoided eflect of the heating coil 28, which,

hot gas discharge of the compressor. The immersed portions of the coilthus immediately affect the temperature of thenow relatively cold oilbody, and the included liquid refrigerant volumes are rapidly evaporatedand driven ofi. It will be understood that the liquid refrigerant willsink in the oil, and thus any oil return action occurring prior toheating will not create a. serious problem, since the valve outlet hole4| is at a relatively high level.

While the invention has been described with respect to a singleembodiment, it will of course be understood that it is susceptible ofmodifications and variations such as are encompassed by the scope of thefollowing claims.

We claim:

1. An oil return device comprising a housin having a refrigerant gasinlet and outlet, a passage within said housing having one terminalcommunicating with a high point within said housing, a body portionextending to the bottom of the housing, and its remaining terminalcommunicating with said .outlet', a float controlled valve mechanismincluding a valve seat disposed within the housing adjacent the bottomthereof, and'an 011 return conduit communicating with said valve seat.

2. An oil return device comprising a housing having a refrigerant gasinlet and outlet, a tubular heating coil disposed within said housingand having one terminal communicating with a high point within thehousing, a bent body portion extending to the bottom of the housing, andits remaining terminal communicating with said outlet, a floatcontrolled valve mechanism including a valve seat disposed within thehousing adjacent the bottom thereof, and an 011 return conduitcommunicating with the valve seat.

3. An oil return device comprising a housing having a refrigerant gasinletand outlet, said inlet being located adjacent the top of thehousing and having an extension within said housing containing aforaminous mass to provide an oil and gas dividing means, said outlethaving atubular extension depending to the bottom of the housing andhaving a terminal extending vertically to a high point in the housing, afloat controlled valve mechanism including a valve seat oilreturn'conduit secured to the exterior of the housing and communicatingwith said seat, a. valve in said guide passage, a lever pivotallycarried on the fitting and having an opening therein for looselyreceiving the end of said valve, a pin extending through the lever andvalve to provide a. pivotal mounting for the valve, and a floatconnected to said lever.

5. An oil returndevice comprising a cylindrical housing having securingmeans at one extremity for mounting the housing on a vertical axis,inlet and outlet fittings disposed in the opposite extremity of thehousing, a tubular heating coil disposed within the housing and havingone terminal communicating with a high point within the housing, a bodyportion extending to the bottom of the housing, and its remainingterminal slidably entered in said outlet fitting, afloat controlledvalve mechanism including a valve seat disposed within the housingadjacent the bottom thereof, and an oil return conduit communicatingwith the valve seat.

GEORGE W. SMITH. JAMES A. SMITH.

